Landowners in Laois insisted they will not back down in their increasingly bitter dispute with Eirgrid over the construction of a major electricity substation near the village of Stradbally.

The long-running dispute, involving a blockade of the proposed substation site at Coolnabacca by a local protest group, escalated last week when local landowners vowed to block ESB from accessing major powerlines in the area.

"We are now escalating our campaign and we will now not only be refusing any access for Eirgrid and ESB to the site, but also to the 400kv and 110kv power lines already in our area," RTS stated.

"We have received huge support from landowners with these power lines. We will not let Eirgrid or ESB in and we have stated to them very clearly that this project is dead. Eirgrid had every opportunity to progress a project which satisfies the identified need but have failed to do so."

RTS claim that the proposed substation is sited above a major aquifer, and poses a threat to water supplies of thousands of families in Laois.

However, Eirgrid insisted that the project had been "rigorously scrutinised through a lengthy planning process".

"We are eager to move to the construction phase of this key piece of local infrastructure that will underpin economic growth for the midlands and are committed to working with the local community and landowners to resolve any issues in relation to the works," Eirgrid stated.

Eirgrid said the presence of layer of "stiff clay subsoil" above the aquifer "will prevent any possible contamination" of the water supply. However, RTS rejected this assertion and pointed out that Eirgrid had already proceeded with works at the Coolnabacca site without planning permission.

ESB said it was investing €110m to upgrade the electricity supply in counties Laois, Kilkenny, Carlow and Kildare.